There have been a variety of tire changing stands which mount on a bench or other structures such as those taught in U.S. Pat. No. 2,693,228 and U.S. Pat. No. 3,867,975. The stand of the '975 patent is affixed to the top of the bench by bolts or other attaching means while the stand of the '228 patent is bolted to the floor. These stands occupy work space on either the bench or the floor, space which cannot be utilized when the tire changer is not being used.
The stand of the '228 patent also teaches the use of a conical wheel hub engaging element; however, the design of this element is such that, if used for a bearing containing wheel hub, the bearings may be damaged by the pressure applied by the conical element. Other patents, such as U.S. Pat. No. 4,299,265 and U.S. Pat. No. 4,433,578 also employ a conical hub engaging means but again, suffer from the same limitation on bearings containing hubs.
With regard to tire changing tools for use with stands, there have been tire mounting tool tips designed to engage tires on rims and remove tires from rims. These tools generally divide into tools for stripping and tools for engaging the tire with the rim. Two of the tools of yesteryear that were used for tire changing are U.S. Pat. No. 1,008,157 and U.S. Pat. No. 1,650,325. Both of these patents teach tool tip configurations which appear to be designed for rims with snap rings for yesteryear's tires, which are removed in the process of removing the tire. These tips have corners that could rip a tube housed within the tire if the tool were used to strip tires with tubes and would not be suited for the tires and rims of today.
U.S. Pat. No. 3,823,756 teaches a double groove tire mounting tool. One groove serves to engage the rim edge while the other groove engages the tire cord. The difficulty with this tip is that the groove engaging the rim is straight, resulting in a gap between the rim and the tool which Can pinch and rip the bead of the tire while engaging the tire with the rim of the wheel. As the size of the rim decreases, this gap grows making it more likely that the beads on small tires will be damaged.
Thus, there is a need for a tire changing system which can be used in combination with a bench and does not reduce the use of the bench surface when the tire changing system is not in use. There is also a need for a tire changing tool which will provide a tip for effective stripping and engaging of tires without endangering a tube contained therein or damaging the rim engaging bead of the tire.